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Rat Ovary (rat + ovary)
Selected AbstractsTemporal and Spatial Distribution of the Cannabinoid Receptors (CB1, CB2) and Fatty Acid Amide Hydroxylase in the Rat OvaryTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010P. Bagavandoss Abstract Although the effects of ,9 -tetrahydrocannabinol (THC) on ovarian physiology have been known for many decades, its mechanism of action in the rat ovary remains poorly understood. The effects of THC and endocannabinoids on many cell types appear to be mediated through the G-protein-coupled CB1 and CB2 receptors. Evidence also suggests that the concentration of the endocannabinoid anandamide is regulated by cellular fatty acid amide hydrolase (FAAH). Therefore, we examined the rat ovary for the presence of CB1 and CB2 receptors and FAAH. The CB1 receptor was present in the ovarian surface epithelium (OSE), the granulosa cells of antral follicles, and the luteal cells of functional corpus luteum (CL). The granulosa cells of small preantral follicles, however, did not express the CB1 receptor. Western analysis also demonstrated the presence of a CB1 receptor. In both preantral and antral follicles, the CB2 receptor was detected only in the oocytes. In the functional CL, the CB2 receptor was detected in the luteal cells. FAAH was codistributed with CB2 receptor in both oocytes and luteal cells. FAAH was also present in the OSE, subepithelial cords of the tunica albuginea (TA) below the OSE, and in cells adjacent to developing preantral follicles. Western analysis also demonstrated the presence of FAAH in oocytes of both preantral and antral follicles. Our observations provide potential explanation for the effects of THC on steroidogenesis in the rat ovary observed by earlier investigators and a role for FAAH in the regulation of ovarian anandamide. Anat Rec 293:1425,1432, 2010. © 2010 Wiley-Liss, Inc. [source] Critical ischemic time for the rat ovary: Experimental study evaluating early histopathologic changesJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2009Ayhan Coskun Abstract The aim of the present study was to determine a critical ischemic time for ovary in an experimental study in rats. An experimental model using slip-knot tying of all ovarian arteries and veins in cycling female rats was developed. Rat ovaries were tied using the technique through an explorative laparotomy. Complete ischemia times of 1, 2 and 3 h were used for the study. At the end of the ischemic times, the ovaries were harvested following 1 h of reperfusion. Histology indicated a gradually increased congestion correlating with the respective increased ischemic times. According to the present findings 2 h complete ischemia yields a significant injury. The model used in the present study may be used for complete ischemia,reperfusion injury of the rat ovary. [source] Cryopreservation of vascularized ovary: An evaluation of histology and function in ratsMICROSURGERY, Issue 5 2008Shijie Qi M.D. Cryopreservation of organs has been investigated to sustain the reproductive function of patients undergoing sterilizing chemotherapy and radiotherapy or reproductive surgery. A modified protocol for whole organ cryopreservation was described and the outcome of cryopreservative ovaries was evaluated, and apoptosis of cryopreservative cells stored for different time period and the viability of cryopreserved cells stored at different temperature was examined in rats. Lewis rat ovarian grafts were perfused for 30 min at 0.35 ml/min with M2 medium containing 0.1M fructose and increasing concentrations of 0,1.5M dimethylsulfoxide, cooled to ,140°C controlled by a computerized program, and stored in liquid nitrogen (,196°C) for 24 hours. After being thawed, ovaries were transplanted to syngeneic recipients after bilateral oophorectomy. Graft functions were monitored postoperatively. The major findings were that: 1) A 100% survival rate of rat ovaries was achieved in this study. Ovarian hormone secretion recovered in 80% rats which had received cryopreservative ovarian grafts. Postoperative serum estradiol levels in the cryopreservative graft group were lower than in the sham surgery control, but much higher than in the bilateral oophorectomy group. 2) Histological examination of cryopreservative ovarian grafts showed preantral and antral follicles. Two gestations were obtained. 3) Estradiol levels remained low in ovariectomized rats while in the oophorectomized rats given cryopreservative ovarian grafts levels started to rise after 14 ± 3 days. 4) The average viability in the cells from cryopreservative ovary organ (,196°C) was about 71 ± 18% compared to 90 ± 9% of fresh cells. This success should encourage further improvement of cryopreservative techniques for large organs. © 2008 Wiley-Liss, Inc. Microsurgery, 2008. [source] Neonatal estrogen exposure inhibits steroidogenesis in the developing rat ovaryDEVELOPMENTAL DYNAMICS, Issue 4 2001Yayoi Ikeda Abstract Treatment of newborn female rats with estrogens significantly inhibits the growth and differentiation of the ovary. To understand the molecular mechanism of estrogen action in the induction of abnormal ovary, we examined the expression profiles of steroidogenic factor 1 (SF-1) and several of its target genes in the developing ovaries after neonatal exposure to synthetic estrogen, estradiol benzoate (EB) by using reverse transcriptase polymerase chain reaction, in situ hybridization, and immunohistochemistry. Morphologic examination indicated inhibitory effects of estrogen on the stratification of follicles and development of theca and interstitial gland during postnatal ovarian differentiation. The expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage cytochrome P450 (P450SCC), which are both essential for steroid biosynthesis, markedly decreased in theca and interstitial cells throughout the postnatal development of the EB-treated ovary. However, expression of the transcriptional activator of the two genes, SF-1 was unaffected in theca and interstitial cells, although the number of these cells was lower in the EB-treated ovary than in the control ovary. The expression of the estrogen mediator, estrogen receptor-, (ER-,), diminished specifically in theca cells at P6 and recovered by P14 in the EB-treated ovary. These results indicate that the effect of estrogens is mediated by means of ER-, resulting in the down-regulation of StAR and P450SCC genes during early postnatal development of the ovary. These results suggest that the abnormal ovarian development by neonatal estrogen treatment is closely correlated with the reduced steroidogenic activity, and the data obtained by using this animal model may account in part the mechanism for aberrant development and function of the ovary in prenatally estrogen-exposed humans. © 2001 Wiley-Liss, Inc. [source] Critical ischemic time for the rat ovary: Experimental study evaluating early histopathologic changesJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2009Ayhan Coskun Abstract The aim of the present study was to determine a critical ischemic time for ovary in an experimental study in rats. An experimental model using slip-knot tying of all ovarian arteries and veins in cycling female rats was developed. Rat ovaries were tied using the technique through an explorative laparotomy. Complete ischemia times of 1, 2 and 3 h were used for the study. At the end of the ischemic times, the ovaries were harvested following 1 h of reperfusion. Histology indicated a gradually increased congestion correlating with the respective increased ischemic times. According to the present findings 2 h complete ischemia yields a significant injury. The model used in the present study may be used for complete ischemia,reperfusion injury of the rat ovary. [source] Temporal and Spatial Distribution of the Cannabinoid Receptors (CB1, CB2) and Fatty Acid Amide Hydroxylase in the Rat OvaryTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2010P. Bagavandoss Abstract Although the effects of ,9 -tetrahydrocannabinol (THC) on ovarian physiology have been known for many decades, its mechanism of action in the rat ovary remains poorly understood. The effects of THC and endocannabinoids on many cell types appear to be mediated through the G-protein-coupled CB1 and CB2 receptors. Evidence also suggests that the concentration of the endocannabinoid anandamide is regulated by cellular fatty acid amide hydrolase (FAAH). Therefore, we examined the rat ovary for the presence of CB1 and CB2 receptors and FAAH. The CB1 receptor was present in the ovarian surface epithelium (OSE), the granulosa cells of antral follicles, and the luteal cells of functional corpus luteum (CL). The granulosa cells of small preantral follicles, however, did not express the CB1 receptor. Western analysis also demonstrated the presence of a CB1 receptor. In both preantral and antral follicles, the CB2 receptor was detected only in the oocytes. In the functional CL, the CB2 receptor was detected in the luteal cells. FAAH was codistributed with CB2 receptor in both oocytes and luteal cells. FAAH was also present in the OSE, subepithelial cords of the tunica albuginea (TA) below the OSE, and in cells adjacent to developing preantral follicles. Western analysis also demonstrated the presence of FAAH in oocytes of both preantral and antral follicles. Our observations provide potential explanation for the effects of THC on steroidogenesis in the rat ovary observed by earlier investigators and a role for FAAH in the regulation of ovarian anandamide. Anat Rec 293:1425,1432, 2010. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||